VEGFA and Kaposi's sarcoma: K1 is a very important protein for modifying host cell metabolism, since it enhances the production of angiogenic factors such as VEGF (vascular-endothelial growth factor) and activates the PI3K/AKT/mTOR cascade, thus playing a significant role in oncogenesis and in the production of the typical angiogenic lesions of KS [50,51].